Optical recording device for telegraphic signaling



. E. BELIN Dec. 16, 1930.

OPTICAL RECORDING DEVICE FOR TELEGRAPHIC SIGNALING Filed Nov. 50, 1928 Aftorney Patented Dec. 16, 1930 nnouann IBELIN, or rams, raanon OPTICAL RECORDING DEVICE FOR TELEGRAPHIC SIGNALING Application filed November 30, 1928; Serial Il'o. 322,841, and in France December. 22, 19 27.

g The object of this invention is to provide a recording device of optical nature for telegraphic signaling, of the type in which the shown and described 'a so-called teletype machinewhich is provided with certain 'arrangements which enable currents to be sent into the linecorresponding to the characters to be transmitted.

. For receiving, the patents above mentioned, disclose an optical arrangement in which the galvanometer that'receives .the.

currents of the line produces by elongations of its string, the illumination of characters corresponding to the characters of the trans-v mitter, and. these illuminated characters are reflected by mirrors disposed in groups or in spiral fashion by means of stepped surfaces, from which a sensitized receiving surface records the signs along a line at regular intervals. i

Certain difiiculties are experienced in pro viding' for the receiving operation in that machine an illumination sufiic ient to enable rapid recording. My present invention, which is about to be described, enables such recording to be produced.

In ,principle, the currents from the line produce theelongation of the string of a galvanometer -produces traces on a film which unwinds in front of it. It will be apparent,

therefore, that if the filmis lighted acrossgalvanometer of the string type, and the said The invention will be more readily under stood by those skilled in the art with reference to the accompanying drawing.

In said drawing:

Figure l is a fragmental view of a portion of film used in carrying out the invention;

F ig. 2 is a face view of a line ofcharacters for use in'conjunction with the film,

Fig, 3 is a diagrammatic view of an optical apparatus constructed in accordance with the'invention, and adapted-t0 be used in connection with an oscillograph or galvanometer of the type shown and described in my aforementioned priorpatents; V i lg. 4 shows a portion of 'Fig' 3 on an enlarged scale.

, A filmF (Fig. 1 is prepared. which is entirely black, with light-transparent spots p; and these spots have an absolutely sharp contour and'very accurately located position, so that the film is thus completely analogous to an opaque perforated band, the perforations being replaced by the blanks produced -by the trace of the string galvanometer.

The film is then placed (see Fig-3) in frontof a line L of signs (Fig. 2) reproducing, for example, the twenty-six letters of the alphabet, towhich there can be adjoined, of course, the ten digits 0, 1, 2 9.- A source of light S enables thedesired amount of light tobe projected, since there is here no case of being limited, as in the v prior constructions, by the smallness of the galvanometer mirror. A mirror M reflects this light upon the film'F which permits it to pass only through the blank of the horizontal line struck thereby,'thus lighting the particular sign of the sign row L which lies behind that blank.

It will be understood that there is need to oscillate the mirror mechanically around its axis R in such a manner as to sweep the entire Width of the film; and in the case illustrated,it will therefore oscillate between two extreme positions M1 and M2 corresponding to the extreme positions RaOa and R202 of the middle ray of the reflected beam. If there is placed behind the sign row L an optical device O,here represented diagrammatically in the form of a converging lens, an image L1 of line L will be formed; but it is desired to collect the rays leaving the optical device on the surfaces 0 0 etc., of the spirally-stepped mirror C described in detail in Patent No. 1,632,164. As shown in that patent, it is essential that all the rays falling on'the surfaces of said mirror be parallel and, in those conditions, a receiving suroptical axis RO, it is desired to obtain parallelrays. With this object in view,th'ere' is positioned behind the optical device 0 a mirror m mounted to oscillate about an axis 1:; the

initial position of this mirror being entirely arbitrary.

. Considering, now, this mirrorm (Fig. 4) articulated at 1, the extreme ray RaOa falls on the mirror at I and is reflected according to the line I 1' the angles i and 71 formed withiithe perpendicular at I to the mirror m being equal. Now consider the sec- .ond ray ZJ and determine what position the mirror must occupy .in order that the reflected ray may be parallel with the reflected ray I 1' or what amounts to the same thing, determine the direction of the perpendicular to the mirror. Take any point J on the ray ZJ and from this point construct a parallel a source of light, an oscillating mirror for reflecting the rays from said source of light upon said film, ailinear element located be hind said film and bearing a row or line of signs, a sensitized surface for selectively recording said signs, and an optical relay between said linear element and said sensitized surface, comprising a lens device in the path of the emitted beam, and a second oscillating mirror connected with the first men tioned oscillating mirror for movement in unison. i

2, Apparatus according to claim 1, in

which each mirror oscillates between two definite positions, the two mirrors moving in reverse manner one with relation to the other.

In testimony whereof I hereunto afiix my signature.

' EDOUARD BELIN to the rays I T the perpendicular to the mirror is obviously the straight line J K that bisects the angle ZJW- and, consequently, t e position m of the mirror is obtained by stri ing from the axis 1 a perpendicular to the straight line J K.' The point of incidence I is then deduced, and the reflected ray I 1' It can then 'be assumed from the foregoing that while the mirror M is oscillating from position M to position M the mirror m 'must oscillate from position m to position m and vice versa." A suitable mechanical connection between the mirrors M and m can readily be. conceived, and may comprise, for example, a lever system embodying a lever 9 connected at one end to mirror m and articulated at the other end atv 2 to a rod .7, the lever itself being fulcrumed. at thepreviously-mentioned -point 1. The other end of the rod 7 is articulated at 3 to one end of a lever 6 fulcrumed between its ends t 4 and articulated at its other end at 5 to a rod 8 attached to mirror M.

'Having described my invention what I claim as new and desire to secure by Letters.

Patent is I v V 1. .Apparatus for-translating telegraphic code characters optically from a movable film. havingsaid' code characters in the form of- I light transparent spots thereon, comprising 

